Oil well pumping equipment and system



2 Sheets-Sheet l E. C. EKSTROMER OIL WELL PUMPING EQUIPMENT AND SYSTEMFiled Jan. 3, 1928 oct. 11, 1932.

Uct. l1, 1932. E. c. EKsTRoMER OIL WELL PUMPING EQUIPMENT AND SYSTEMFiied Jan. 5. 1928 2 Sheets-Sheet INVENTOR. 6. 25J/bmw iras vtammenatuur EDWARD C. EKSTROMER, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR, BYDIRECT AND MESNE ASSIGNMENTS, F ONE-HALF TO JAMES F. GALLAGHEIR, OFBOSTON, MASSA- CHUSETTS, AND ONE-HALF TO THE EDWARD C. EKSTROMERCORPORATION, OF RENO, NEVADA, A CORPORATION OIE' NEVADA` Y ont.` wmPUMPING' EQUIPMENT AND ssrsrn'Ji/ry application linea January 3, 192s.serial No. 244,208.

My present invention relates to oil Well pumping apparatus and a controlmeans therefor and more particularly to an improved arrangement ofelectric motors and\ E control. l

An object of my vinvention is to provide an improved form of oil wellpump wherein the Aelectric motors and the pump can be low-v ered as aunit into the well.

Another object of my invention is to provide an improved arrangement ofmotors for oil well pumps and the like, whereby a power unit of any'desiredcapacity can be obtained without necessitating an enlargement ofthe well casing.l

A further object of my invention is to pro-v vide an electrically drivenreciprocating pump unit for deep well pumping which can be lowered in acasing and controlledfrom the surface without the use of reversing Yswitches within the well.

Another object of my invention is to provide a driving means for an oilwell pump which will permit the use of a number of individual motors. y

A further object of my invention is to provide a control system wherebya reversible electric motor Jfor driving a reciprocating pump can bereversed and the pump Stroke varied without the use of reversing limitswitches. p I

Another object of my invention is to provide an improved reversiblemotor drive for an oil well reciprocating pump wherein a plurality ofmotors operating in tandem are used to operate the pump. 1

A further object of my invention is to provide a system of control for aplurality of motors acting in tandem upon the same load whereby thenumber of motors so operating will be controlled in response tovariations in the load.

Other objects and advantageous `features, some-of which with theforegoing will be set forth at length in the following descriptionwherein I have outlined in 'full that form of apparatus which I haveselected for illustratlon in the drawings accompanying and 'forming apart of this specification. 5G At the present time oil well pumps of thereciprocating type are operated by means of a motive power unit locatedon the surface at the top of the well. These units comprise a primemover, a walking beam which is oscillated by means of a pitman connectedto the` prime mover and a sucker rod which Arod extends downwardly intothe well where it connects to the moving parts of the pump. The use ofsuch a sucker rod is attended with many undesirable features, some ofwhich are: stretching, whipping7 and its weight. All of theseundesirable' features become more exaggeratedas the depth of the wellincreases and it is therefore desirable that some means be providedwhereby these diliticulties can be overcome.

In order to overcome these difficulties, I propose to construct a primemover element for operating a reciprocating oil well pump which can belowered into the well and which will dispense with the use of the abovereferred to motive power units and its cooperating sucker rod. Thegreatest obstacle in providing such a unit is in providing a unit smallenough to be inserted into the well casing, which casing is of arelatively small diameter for such a purpose. This restriction in thesize of such a unit, however, applies only to its horizontal ordiametrical dimensions and since it can be made of almost any desiredlength, I propose to build an electro-mechanical power'unit by employinga plurality of smaller units, each of which `is small enough tol beinserted in the well.

These units are then connected mechanically together through a suitablerack which is adapted to be connected with the sucker rod of a pumpwhich will be secured to the lowe end of the motive power unit.

A further feature of my invention isin the manner of controlling theseelectro-mechanical power units. It is essential that no sparking orelectric arcs be present within the well because of the danger ofexplosions which might be caused by the gases present. In order toovercome this diliculty and make my device safe under these conditions,I provide motive power units of the induction type and control thedirection of rotation or movement thereof by means of a controller orreversing switch located at the top of the well which can be located atany convenient and safe point thereabout.

For a better understanding of my invention, reference should be had tothe accompanying drawings, in whichI have shown by way of illustrationand not of limitation apparatus which represents the best embodi- .mentof my device now known to me. I desire to have it understood, however,that many changes and modifications can be made therein withoutdeparting from the spirit of my invention.

In these drawings- Fig. 1 is a fragmentary vertical sectional view of amotive power unit built in accordance with my invention and located asit is used in an oil well casing,

Fig. 2 is a view similar to at right angles thereto,

Fig. 3 is a partial sectional view taken along the line III-III `of Fig.1, looking in direction vof arrows,

Figs. 4, 5, and 6 are sectional views taken respectively along linesIV-IV, V-V, and VI-VI of Fig. 1, looking in direction of arrows,

Fig. 7 is a partial sectional view looking along line VII-VII of Fig. 1,looking npward, as indicated by arrows,

Fig. 8 is a fragmentary vertical sectional view similar to that of Fig.2 together with Fig. taken a schematic showing of the controller or,y

reversing switch, and

Figs. 9 and 10 are diagrammatic wiring lay-outs showing the electricalcontrol circuits employed with the apparatus herein disclosed.

In Figs. 1 and 2 of the drawings I show a well bore having a casing 10therein as is the practice in wells of this kind. Located within thecasing-10 I also show a housing 11 which is substantially circular incross section. This housing is of such a size that it will slide freelywithin the casing 10 so that it can be lowered into the well by `meansof an oil discharge pipe 12 to which it is secured. The housing 11 isprovided with end members 13 and 14 which are secured respectively tothe top and bottom thereof. These end members are cored out and areprovided with ports which align with suitable passageways for the oil,which I have designated by the numeral 15, through the housing member11. 'Ihe upper member 13 is provided with a central opening into whichthe discharge pipe 12 is threaded and it is also provided with anopening through which an electric conduit 16y can be inserted and thelower member 14 is also provided with ports which align with thepassages 15, a central opening to which the pump is secured, and apacking gland 17 through which a pump sucker rod 18 projects. When thehousing 11 and the end members 13 and 14 are secured together, anenclosing housing is produced in which electrical apparatus or the likecan be enclosed free from contamination by oil and the like, thepassageways 15 cooperating with the end members and their respectiveports to provide a passageway for the pumped oil around the enclosedportion of the housing.

Located within the housing formed as above, I provide a plurality ofelectric motor units 19 which are securely fastened together. In thedrawing I have shown three such motor units, but I desire to have itunderstood that this is merely by way of illustration and that anynecessary number of such units can be used and I have therefore made thehousing member 11 of a sufiicient length to permit the insertion of thedesired number of such motors and in the event that as located centrallyof the housing 11 and at a sufficient distance from the end member 14 topermit the sucker rod 18 to be recipro cated therebelow withoutinterfering with The motor elements are its normal stroke. each providedwith a pinion 21 and arranged adjacent the pinions 21 I provide a rack22 which is adapted to move with a reciprocating motion along a guideway23 as the motor units 19 rotate irst in one direction and then in theother. 'Ihe rack 22 projects downwardly below the motor units and at itslower end it is provided with an offset arm 24 to which the sucker rod18 is attached. Arranged within the space between the motor units 19 andthe end member 14 I provide buffers or stops 25 and 26 which serve tolimit the stroke of the rack so as to prevent it from becomingdisengaged from* the pinions 21.

Y Referring to Figs. 4, 5, and 6 it .will he Seen that the housingmember 11 has substantially three longitudinally extending openings, theouter ones of which constitute the oil passages 15. From these views ofthe drawings it will be seen that the central opening is substantiallylarger than the passageways 15 and that recesses are provided in' thesides thereof with which the motor units 19 engage. It will also be seenthat the rack 22 and its cooperating guide 23 are also located in thiscompartment. It should be noted that I have provided fins 27 whichproject from the motor supporting partition of the housing 11 into theoil passages 15. These fins serve to conduct the heat generated by themotor units 19 to the oil bemg pumped so that the heat will be car-,ried away thereby and thus insure a conmy invention after havingdetermined the number of units' required, the rack will be properlyplaced therein and after the motor umts are assembled in a vert-icalline, as sug-` gested above, and after the desired connections are made,this assembly will be inserted in the housing, the lowermost motor unitbeing forced against a supporting pa-rtition 29. If the number of motorunits used are not suiicient to completely fill the housing 11, spacingmembers 2,0 are placed end to end with the motors until the motorenclosing space is completely taken up. These spacing members20 are madeof substantially the same dimensions as the motor units 19 so that,should it be found necessary to add a mot-or unit, it can be done byreplacing one of these spacers with a motor. 1t should be pointed outhere that other means of securing the motors within the casing might beused and that this specic arrangement is 4not important. After themembers are. thus assembled the top member 13 will be secured in place.The opening through which the conduit 16 extends' will then be securelyclosed by means ofa suitable packing. The pump sucker rod 18 and thelower end can then be secured ,in place grid, after the unit is securedto the discharge pipe-12, the whole can then be lowered into the well,where it can be operated a-s will hereinafter appear.

The motive power units 19 in the present embodiment of my invention areshown as of the induction motor type. These motors are provided with analternating current winding, which in the present instance has threephases.. vThe primary windings are of the. distributed type and therotor or secondary winding is of squirrel-cage construction, the' secondary winding preferably being one of high resistance so that a highstarting torque will be produced thereby. Beca-use of the absence ofsliding contacts which might cause sparking, these motors areparticularly suited to my device.l In order to further eliminate thepossibility of sparking because of changing electrical circuits, Ipropose to` provide a reversing means for these motors which can belocated at the top of the well and at a sulficient distance therefrom toavoid any danger 1 from explosions due to ignition of the gases present.The arrangement of rack and the size ofthe pinions 21 are proportionedso that in producing a` stroke in the neighborhood of thirty inches, themotor units 19 turn over from ten to twenty revolutions in eachdirection as the current flow thereto is reversed. By referring to Figs.8, 9, and 10 ofthe drawings it will be seen that the cable 28 terminatesin three conductors which Arepresent the three conductors of athree-phase alternating current power circuit.` rll`hese conductors areconnected to a suitable terminal block 30 which is provided with brushesin contact with a rotating drum 31. Opposite the terminal block 30 lshow a. second similar terminal block 32 also having brushes whichengage the opposite side of the drum 31. The brushes upon the terminalblock 32 are cennected directly to a suitable source of power by meansof a switch 33 which connects with a suitable transformer 34. rlhe drum31 is provided with three sets of contacts 35 arranged radiallytherearound, the oppositely disposed contacts being arranged withinterlinking connections so 'that as the drum is rotated two of thephases of the three-phase circuit will be reversed to thus produce areversal of the energy supplied to the motor units 19. The drum 31 ismounted upon suitable journals 36 and is continuously driven by avariable speed motor 37 through a suitable speed reducing gear 38.Connected within the circuit ofthe motor 37 l provide a speed controller39 by means of which the operator can vary the speed of the motor 37 Theoperator can then, by manipulation of the speed controller 39, regulatethe number.

of reversals of current per unit of time and thus control the speedofthe pump and also the stroke thereo f In these drawings I have shownonly three motorunits 19 connected to the power lines, but it should beunderstood that any necessary number of these units 19 'can be used, theonly limiting factor in this respect being in the length of the housing11, and, since this housing can be of any length, this factor need notnecessarily constitute a limitation. By referring particularly to Figs.9 and 10 it will be seen that the segments 35 of the reversing switchare connected so that paths for current are provided between theoppositely disposed hand conductors lof the three-phase circuit and thuseffect a reversal of which, as'is well known, will versal in thedirection induction motor units 19.

The modification illustrated in Fig. 10 of the drawings involves theprovision of additional electro-magnetic contactors 42 and 43 phaserotation produce a re.- of rotation of the ier ` thereon does notrequire all of the motor units.

Because of the manner of connecting the coils 44 and 45 in series withthe power line of at least one'or a number of the motor units, they willinsure the operation of a sullicient number of the motor units toprovide the necessary amount of starting torque and lalso shorten theperiod of excitation of some of the motors when they are not required indriving the pump. This latter feature will be found desirable as it willreduce the combined heating effect of the motors over that which wouldexist if all of the motors were continuously energized, as previouslysuggested. In this figure of the drawings I have shown but three motorunits with a contacter in the circuit of each unit,'but I desire to haveit understood that a greater number of motor units may and will no doubtbe used andunder these conditions, instead of providing contactors ineach motor unit circuit, I may arrange the units in groups and provide acon` tactor for each group as, for instance, instead.

of a single motor as shown in the drawings, each of these moto-rrepresentations may represent a group of two or more such units.

Vhile I` dol not limit myself to the use of an induction motor type ofmotive power unit, it will be seen that this type of unit Will, becauseof its starting characteristics, be admii-ably suited to this use, as itwill produce a starting torque greatly in excess of its runing` torqueand since the frequent reversals thereof will necessitate frequentstarting, this characteristic of the unit is very desirable.

It should be pointed out here that these in-v dividual units .19 aredesigned so that they will not dangerously overheat when stalled.ln'ot-hcr words, they will operate more in the nature of atorqueproducing unit than a motor in the strict sense of the word. As a result0f this feature, it will be possible to operate the rack 22 bypermitting it to engage the stops 25 and 26 at the ends of its travelbefore a reversal of the phase" rotation of the motor fields iseffected. It will, however, be found desirable to operate the rack 22between these limits and rely upon the stops 25 and 26 only underextreme conditions or where'a maximum stroke is required. In thisconnection it.

should be noted that the stroke ofthe rack 22, and therefore the strokeof the sucker rod.

`18, can be varied by speeding up the operation of the reversing switchydrum 31. This will shorten the period of excitation of the motor unitsand cause them to lreverse more often and thus produce a shorter strokeof the rack 22, as will hereinafter appear. This feature of my inventionmakes it possible to shorten the stroke so that the sucker rod will bereciprocated very rapidly with a comparatively short stroke and whenoperated in this fashion, the device will be very eective in shaking upthe well without having to make external adjustments such as are nownecessary with the present types of pump driving means.

In order that a clearer understanding of my invention may be had, Ishall describe a typical device which I' have designed for pumping theaverage well. The reciprocating pump has a normal stroke ofapproximately thirty inches and requires from five to seven and one-halfhorse-power to operate it at a. speed of from fifteen to thirty strokesper minute. The individual motor units are capable of exertingapproximately one-fifth of a horse-power and have a starting torque ofsubstantially four times their normal running torque, or lin otherwords, a starting .torque of approximately four-fifths of a horse-power.TheV number of such units which will be required with a pump of theabove type will therefore be approximately ten units. If it is foundthat the pump requires more units than anticipated, these additionalunit-s Ican easily be added without enlarging the housing 1l by merelysubstituting a motor unitfor one of the spacing blocks 20. The pitchdiameter of the pinions 21 is approximately one inch. This will requiresubstantially ten revolutions of the rotor of the motor unit to effect acomplete stroke of the rack in one direction and, as a result, it

will be seen that these motors will not attain a as shown by way ofillustration in Fig. 8. In

this figure of the drawings the pump is shown at the lower end of itsstroke with the contactsl 35 of the reversing controller 3l completing acircuit from the transformer 34 to the motors, which circuit, it isfurther assumed, is just opening. As the drum 31 continues to rotate thefollowing setof contacts 35 will engage the brushes upon the terminalblocks 30 and 32 and re-establish, the electric power circuit, thecircuit in this case, however` having a direction of phase rotationopposite to that of the former circuit. This will energize the motorunits 19 in the reverse direction and cause them to rotate clockwise asviewed in this ligure of the drawings and cause the rack to be movedupwardly thus the rack' t'o be moved downwardly to e'ect the reversestroke of the pump. This operation will continue as long as thecontroller drum 3l is caused to rotate and if it is desired to regulatethe-rate of motor reversals, this will be done by varying the speed ofthe controller driving motor 37 by means of the manual control means 39.

While I have shown the preferred form of my invention as now known tome, it is to be understood that various changes may be made in itsconstruction without departing from the spirit of the invention asdefined in the appended claims.

Having thus described my invention, what I claim and desire to secure byLetters Patswitch between ent is l. In a control system forelectro-mechanically driven reciprocating pumps of the characterdescribed, the combination of a sucker rod, a rack connected to saidsucker rod, an electro-mechanical means for driving said rack, a sourceof polyphase alternating current power for supplying current to saidelectro-mechanical means, and a reversing said electro-mechanical meansand said source of polyphase current for periodically reversing theVphase rotation of said Vcurrent and thereby cause said rack and suckerrod to be driven with a reciprov cating motion, characterized by thefact that the periodicity of phase reversals may bev varied to determinethe stroke of the sucker rod without resort'to other circuitinterrupting means.

2. In a control system for electro-mechan-- ically driven reciprocatingpumps of the character described, the combination of a reciprocatingpump, a sucker rod for said pump, a rack connected to said sucker rodand mounted to be driven with a reciprocating movement, anlelectro-mechanical means for driving said rack, a source of polyphasealternating current electric power for supplying-currentjo saidelectro-mechanical means, a continuously operating phase reversingswitch in said alternating current supply for periodically reversing thephase rotation of the current supplied to said electro-mechanical means,whereby areciprocating motion will be imparted to said rack, and

ymeans for varying the frequency of operation of said phase reverslngswltch to con-` trol the stroke of the sucker rod.

3. In a drive for the sucker rod of reciprocating oil well pumps, thecombination of a discharge pipe adapted to be lowered into an oil well,an induction motor unit as a motive power means located at 4the bottomend of said discharge pipe, a pump havingv its outlet connected withsaid discharge pipe, a sucker rod for said pump adapted to be driven bysaid motive power means, a source of polyphase alternating current forsaid induction motor unit, a periodically operating reversing switch atthe top of the well discharge pipe and connected between the motor unitand said source of current to periodically reverse the phase rotation ofthe alternating current supplied to the motor unit, whereby thedirection of rotation of the motor unit will be periodically reversed,and a driving connection -.between said motor unit and the sucker rodfor imparting a reciprocating movement to the pump sucker rod as themotor unit is reversed.

4. In a control system for reciprocating oil well pumps, the combinationoiga dispcharge pipe adapted to be lowered into an ly reverse the phaserotation of the current supplied to said motor, a reciprocating pumphaving its outlet connected with said discharge pipe, a sucker rod foroperating the pump, and a mechanical driving connection between saidmotor and said sucker rod for imparting a reciprocating motion to thepump sucker rod as the direction of rotation of said motor isperiodically reversed.

5. In an alternating current motor control system for pumps of the`character described, the combination of a discharge pipe adapted to belowered into an oil well, a polyphase alternating current electro-motivedevice supported upon the bottom end of said discharge pipe and adaptedto be submerged in an oil well, a reciprocating pump having its outletconnected to the lower end of said discharge pipe, a sucker rod for saidpump, a source of alternating current for said electro-motive device, aphase reversing switch between the electro-motivedevice and said sourceof alternating current located at the top end of the well dischargepipe, means for operating said phase reversing switch t'o periodicallyreverse the phase rotation of the current supplied to saidelectro-motive device, and a driving connection between saidelectro-motive device and said sucker rod, characterized by the factthat as the phase rotation of the current supplied to said device isperiodically reversed at the top of the well a reciprocating motion willbe imparted to the pump sucker rod.

6. `A drive for reciprocating oil well pumps and the like comprising anoil well discharge pipe, a pump-having, its outlet communicating withsaid discharge pipe, a sucker rod for operating said pump, a rackconnected with said sucker rod, a plurality of reversible inductionmotor units geared to said rack, said rack and said motor units beingenclosed in a housing mounted upon the bottom end of said discharge pipeandadapted to be lowered into a well, a current conducting cable forAconnecting said motor units with a source of current supply, andcurrent reversing means at the top end of said discharge pipe forcontrolling and reversing the vdirection of rotation of said motors tothereby impart a reciprocating movementto said rack and sucker rod andoperate the pump.

7. An electro-mechanical drive for the sucker rod of a reciprocatingpump comprising an oil discharge pipe adapted to be lowered into a well,a plurality of reversible motor units having pinions upon their drivingends arranged in alignment and supported at the bottom end of saiddischarge pipe, a pump having its outlet communicating with said oildischarge pipe, a sucker rod for said pump, a rack connected with saidsucker rod extending upwardly and meshing with said pinions, and meansat the top end of said discharge pipe for periodically reversing thedirection of rotation of said motor units, whereby a reciprocatingmovement will be imparted to said sucker rod and pump as said motorsareperiodically reversed.

8. In a drive for the sucker rod of reciprocating oil well pumps, thecombination of a discharge pipe adapted to be lowered into an oil well,an induction motor unit as a motive power means located at the bottomend of said discharge pipe, a pump having its outlet communicating withsaid discharge pipe and adapted to be driven by said motive power means,a source of polyphase alternating current for said induction motor unit,a periodically operating reversing switch at the top of the welldischarge pipe and connected between the motor unit and said source ofcurrent to periodically reverse the phase rotation ofthe alternatingcurrent supplied to the motor unit, whereby'the direction of rotation ofthe motor unit will be periodically reversed, and a driving connectionbetween said motor unit and the pump for operating the pump as the motorunit is reversed.

9. In an alternating current motor control system for pumps of thecharacter described, the combination of a discharge pipe adapted to belowered into an oil well, a polyphase alternating current electromotivedevice supported upon the bottom end of said discharge pipe and'adaptedto be submerged in an oil well, a pump connected-to pump oil into saiddischarge pipe, a source of alternating current for said electro-motivedevice, a phaseI reversing switch between the electromotive device andsaid source of alternating current located at the top end of the welldischarge pipe, means for operating said phase reversing switch toperiodically reverse the phase rotation of the current supplied to saidelectro-motive device, and a driving connection between saidelectro-motive device and said pump, characterized by the fact that asthe phase rotation of the current supplied to said device isperiodically reversed at the top of the well a pumping motion will beimparted to the pump.

10. An electro-mechanical drive for a reciprocating pump comprising anoil discharge pipe adapted to be lowered into a well, a plurality ofreversible motor units having pinions upon their driving ends arrangedin alignment and supported upon the bottom end of said discharge pipe, areciprocating pump connected to pump oil into said discharge pipe, arack adapted to be driven by said pinions and connected to operate saidpump, and means at the top end of said discharge pipe for periodicallylreversing the direction of rotation of said motor units,

whereby a reciprocating movement will bev imparted yto Athe pump as saidmotors are periodically reversed.

EDWARD C. EKSTROMER.

